The present invention relates generally to enclosures for telecommunications equipment. More particularly, the invention relates to a distribution terminal for interconnecting one or more drop cables with a distribution cable at an access point in a telecommunications network.
Telecommunications service providers are currently developing networks consisting entirely of fiber optic components to meet the demand for high bandwidth communications service to businesses and homes. These xe2x80x9call-opticalxe2x80x9d telecommunications networks require service terminals, referred to herein as xe2x80x9cdistributionxe2x80x9d terminals, located at access points along the network for interconnecting one or more drop cables to a distribution cable from the service provider. In some instances, certain optical fibers of the distribution cable are connected to optical fibers of a drop cable that is routed directly to the business or home of a subscriber of the communications service. In other instances, the drop cable is routed from the terminal to yet another access point along the telecommunications network to serve as a further distribution cable for additional drop cables. The further distribution cable is sometimes referred to in the art as a branch or xe2x80x9cfeederxe2x80x9d cable. The optical fiber network may be configured in many different ways, but typically, is configured with a plurality of main distribution cables from the service provider that are interconnected with feeder cables at various network access points. The feeder cables in turn are interconnected with further feeder cables, or with drop cables containing optical fibers that are routed directly to communications equipment belonging to subscribers. As used herein, the term xe2x80x9cdistribution cablexe2x80x9d includes both main distribution cables and feeder cables, as those terms are presently understood by one skilled in the art.
In existing telecommunications networks, the drop cables are typically interconnected with a distribution cable within a splice closure suspended from an aerial telephone cable strand or mounted on a telephone pole. An aerial splice closure is a particular type of network access point terminal that generally includes a longitudinal frame enclosed by a cylindrical housing. The cylindrical housing is intended to optimize the number of optical fiber connections that can be made within the closure. During initial configuration, the fiber management area within the closure for the optical fiber connections may be readily accessible. However, due to the aerial location of the closure and the congestion of the fiber management area, substantial expertise and experience are required to subsequently reconfigure the optical fiber connections. In particular, it is often difficult to locate and identify the optical fibers of the distribution cable that are interconnected with a particular drop cable. Once identified, the opportunity to re-route existing drop cables or to install additional drop cables without exceeding the minimum bend radius of the optical fibers is limited by the complicated fiber routing and the congestion of the fiber management area. The situation is further exacerbated because conventional aerial closures do not include a cover that can be positioned at the aerial location so as to provide substantially unrestricted access to the optical fiber connections within the closure.
While fiber optic networks have traditionally served as the back bone or trunk line of telecommunication networks to transmit signals over relatively long distances, all-optical networks are gradually being extended closer to the end points of the network. In this regard, fiber optic networks are being developed that deliver fiber-to-the-home, fiber-to-the-business, fiber-to-the-desk, and the like. In each of these applications, the distribution terminal must be capable of interconnecting the optical fibers of the drop cables with the optical fibers of the distribution cable to establish the desired optical connections. For example, a distribution terminal utilized in a fiber-to-the-home, fiber-to-the-business, or fiber-to-the-desk application may be mounted on a distribution cable along with one or more drop cables such that certain optical fibers of the distribution cable extend uninterrupted through the terminal, while other optical fibers of the distribution cable are joined with optical fibers of the drop cables. In certain instances, the optical fibers of the drop cables may be joined directly to the optical fibers of the distribution cable at the access point using conventional splicing techniques. In other instances, the optical fibers of the drop cables and the optical fibers of the distribution cable are first spliced to a short length of optical fiber having an optical connector attached at the other end, referred to in the art as a xe2x80x9cpigtail.xe2x80x9d The pigtails are then connected to opposite sides of an adapter to interconnect the drop cables with the distribution cable. As used herein, the term xe2x80x9cconnectorizedxe2x80x9d refers to an optical fiber that has been spliced to a pigtail at an access point. Optical fibers are connectorized to permit the optical fiber connections to be subsequently reconfigured at the access point without the optical fibers having to be first separated, then cleaned and polished, and then re-spliced to other optical fibers. In still other instances, the optical fibers of the drop cables may be connectorized at the time of manufacture, referred to herein as xe2x80x9cpre-connectorized,xe2x80x9d and connected at the access point to optical fibers of the distribution cable that have been connectorized. The pre-connectorized optical fibers of the drop cables are interconnected with the connectorized optical fibers of the distribution cable utilizing one or more adapters in a known manner.
Typically, a distribution terminal, for example a conventional aerial splice closure, includes one or more splice trays, coupler trays and/or connector panels that facilitate the splicing or connecting of respective pairs of optical fibers. Most terminals house a large number of optical fiber connections, and thus, include a plurality of splice trays, coupler trays and/or connector panels stacked one upon another or stored in separate compartments within the terminal. The trays and panels are preferably secured within the terminal such that they are fixed in position once the terminal has been initially configured and is placed into service. The trays and panels should not shift or otherwise move once the terminal is placed into service since any shifting or other movement could harm the optical fiber connections. While the trays and panels are desirably fixed in position, the terminal is also preferably designed so that the trays and both sides of the panels can be readily accessed by a field technician during the initial configuration of the terminal in which the optical fiber connections are established and during any subsequent reconfiguration of the terminal wherein at least some of the optical fiber connections are modified. In either instance, the trays and panels must be supported and securely retained in a convenient location that provides the field technician with access to the optical fiber connections housed within the terminal. Reconfiguring an aerial terminal is especially difficult, particularly in applications, such as previously discussed, where at least some of the optical fibers of the distribution cable extend uninterrupted through the terminal. In such instances, sometimes referred to as xe2x80x9ctaut sheathxe2x80x9d applications, the terminal cannot be removed from the distribution cable to reconfigure the optical fiber connections on a work platform located on the ground. Accordingly, the terminal must be reconfigured from a ladder or from an aerial bucket that is positioned in close proximity to the terminal. It is known to provide a work platform on the ladder or aerial bucket. However, the work platform provided on the ladder or aerial bucket cannot always be positioned sufficiently close to the terminal, for example when the cover of the terminal interferes with the ladder or aerial bucket in the opened position. Furthermore, work platforms provided on ladders and aerial buckets typically are not suited for securely retaining the various sized trays and panels that may be housed within aerial terminals.